A vehicle HVAC system typically includes a heater core positioned in an engine compartment on an opposite side of a firewall or dash from the passenger. In a conventional configuration, a pair of heater pipes or tubes extend from the heater core and an HVAC case through a passage in the dash to mate with appropriate delivery hardware in the passenger compartment. The pipes usually comprise stainless steel, plastic or rubber.
A seal is generally provided in the heater pipe assembly between the heater pipes and the dash. The seal is typically designed to prevent water intrusion from the engine compartment to the passenger compartment. The seal generally is not independently held to the dash. During assembly, proper seal orientation relies on fore/aft positioning of the HVAC case with respect to the dash.
While conventional seal configurations for a dash mounted HVAC unit provide an adequate seal between the engine compartment and the passenger compartment for water intrusion purposes, they offer minimal noise reduction capability.